A new round of clinical data reported today at the annual meeting of the American Society for Bone and Mineral Research lends further credence to GlaxoSmithKline and Roche’s Bonviva as an effective once-monthly therapy for postmenopausal osteoporosis.

Results from the three-year MOBILE extension study not only confirmed that Bonviva (ibandronate) is able to significantly boost both lumbar spine and hip bone mineral density - and therefore reduce fracture risk by association - but also reinforced the agent’s strong safety profile, with just 1.9% of participants dropping out due to side effects.

“The three-year MOBILE extension data show a BMD increase of 1.5% at the lumbar spine and 0.3% at the hip compared to the end of year two with monthly dosing of ibandronate 150mg. This demonstrates a robust and continuing effect on BMD with a convenient dosing regimen and excellent safety profile,” Dr Michael Lewiecki, MOBILE lead study author from the New Mexico Clinical Research & Osteoporosis Center, told PharmaTimes. “While there are no studies directly comparing the anti-fracture efficacy of bisphosphonates, monthly oral ibandronate represents a welcome addition to our choices for therapeutic agents to reduce the risk of osteoporotic fractures,” he added.

And, importantly, data from the PERSIST trial presented at the meeting was able to demonstrate, for the first time, that women taking once-monthly Bonviva alongside a specially-designed patient support programme were more likely to stick to their treatment than those on Merck & Co’s once-weekly rival Fosamax (alendronate). A 47% improvement in persistence was recorded in the Bonviva group over a six-month period, indicating that the combination of less-frequent dosing and patient support can have a powerful effect on adherence to therapy and, consequently, treatment outcomes.

“Following on from the BALTO 1 study, which showed that 66.1% preferred the once-monthly ibandronate, the PERSIST study demonstrates that a patient friendly treatment regime plus patient education and support significantly improves persistence with therapy and therefore reduces the burden of osteoporotic fracture,” Dr Alun Cooper, a GP and lead investigator of PERSIST, told PharmaTimes.

Bisphosphonate drugs such as Bonviva, Fosamax and Actonel (risedronate) from Procter & Gamble/Sanofi-Aventis currently represent the gold-standard osteoporosis treatment, but patient adherence is notoriously low because of these drugs’ gastrointestinal side effects and complicated dosing regimens.

With its simple dosing regimen and favourable tolerability profile, it is widely hoped that Bonviva will not only help patients suffering from the disease, but also alleviate the economic burden related to treating osteoporosis on the National Health Service, which is currently estimated to be around £1.7 billion a year.